The present invention relates generally to the field of printers and, in particular, to printers with print ribbons.
Compact disc publishing and replicating systems often use a printer to place a label on the compact disc (CD). Several options are available for printing. One option is to print directly onto the disc using an ink jet printer or using a thermal transfer printer.
An important advantage that thermal transfer printers enjoy over inkjet printers used to label CDs is that they do not require specially coated CDs to accept the ink from the printing process. Although printable discs are available, they are more expensive than traditional un-coated media. Further, thermal transfer printers can print with greater speed and print on discs prepared with an inexpensive lacquer coating.
A thermal transfer printer typically includes a print head, a thermal transfer ribbon, and assembly to move the CD past the print head. The print head contains an array of thermal elements, and the thermal transfer ribbon is a plastic film with a transferable coating, such as a pigmented wax or resin compound, deposited on one side. The print head contacts the thermal transfer ribbon during printing, and the thermal transfer ribbon contacts the media. The transferable coating is deposited on the media by heating areas of the thermal transfer ribbon. Printing occurs by moving thermal transfer ribbon and the media at the same rate across the print head, while firing the heating elements in a desired pattern.
Multi-colored thermal transfer ribbon is used to print multi-colored images on a CD, and single-colored thermal transfer ribbon is used to print single-colored images on a CD. Multi-colored thermal transfer ribbon typically has a succession of tri-color panels, e.g., yellow, magenta, and cyan, and is usually consumed at a fixed rate because a different, previously unused tri-color panel is consumed for each print request. For example, if each print request corresponds to printing on a single CD, one tri-color panel is used for the CD.
In contrast, single-colored thermal transfer ribbon is usually consumed at a variable rate because only an approximate amount of thermal transfer ribbon that is required for a given print request is consumed. For example, a print request may involve printing a single line of text on a CD and thus approximately an amount of single-colored thermal transfer ribbon required to print the single line is used. Another print request may involve printing several lines of text on a CD, and in this case, approximately an amount of single-colored thermal transfer ribbon required to print several lines is used. The variable consumption rate of single-colored thermal transfer ribbon makes it difficult to monitor consumption of single-colored thermal transfer ribbon and thus to determine how much thermal transfer ribbon is available at any given time and how many print requests can be fulfilled with the available ribbon.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for monitoring consumption of ribbon of a printer.
The above-mentioned problems with monitoring variable consumption of ribbon of printers and other problems are addressed by embodiments of the present invention and will be understood by reading and studying the following specification.
In one embodiment, a method for monitoring consumption of a print ribbon of a thermal printer is provided. The method includes pressing the print ribbon against a medium located on a drawer of the thermal printer using a thermal print head of the thermal printer. The method includes moving the drawer and the print ribbon simultaneously and at substantially the same rate past the thermal print head so as to deposit a transferable coating of the print ribbon on the medium, whereby printing an image on the medium. Measuring a distance moved by the drawer while pressing the print ribbon against the medium and equating the distance moved by the drawer to an amount of print ribbon consumed are also included in the method.
In another embodiment, a method for installing a ribbon within a printer is provided. The method includes disposing the ribbon within the printer so that a leader of the ribbon remains in an active sensing area. The method also includes detecting an indicator on the leader using a sensor, where detecting the indicator gives an amount of ribbon initially available for printing.
In another embodiment, a thermal printer is provided. The thermal printer includes a drawer to hold a medium for printing upon by the thermal printer. A thermal print head is included for pressing a print ribbon against the medium during printing. Moving the drawer and the print ribbon simultaneously and at substantially the same rate past the thermal print head while the thermal print head presses the print ribbon against the medium deposits a transferable coating of the print ribbon on the medium to print an image on the medium. A sensor is included for detecting an indicator on the print ribbon to give an amount of ribbon initially available for printing. Also included is a controller adapted to store an initial numerical quantity indicative of the amount of ribbon initially available for printing, to measure a distance moved by the drawer while the thermal print head presses the print ribbon against the medium, to subtract the distance from the initial numerical quantity indicative of the amount of ribbon initially available for printing to update the amount of the thermal transfer ribbon available for printing, and to store an updated numerical quantity indicative of the updated amount of the thermal transfer ribbon available for printing.
Additional embodiments are described and claimed.